I have a source for bat guano which I want to use as fertalizer. I read that there is a high ammonia content in the fumes which might be hazardous. Also I can't find any info on how long to age it before I use it. Has any one had an experience using it? Thanks muchly in advance.

I can tell you from first hand experience you definitely need to to use it sparingly around the plants.
Back IN Illinois a friend of ours had bats in the barn and we wen t and got a bunch of it. hubby always put stuff on the inpatients and when it used the bat guano and didn't do it sparingly he almost killed all of them off.
Once it got watered down the plants were huge but it took awhile for them to recover